Accidental extravasation of infusions or drugs such as Propofol, Iohexol etc.

Lithotomy positioning during surgery

Streptococcal infections

Pathogenesis

Normal interstitial pressure is 8mm of mercury in adults and 10-15mm Hg in children.

Trauma leads to inflammation which leads to vasodilation and increased capillary permeability resulting in edema which increases interstitial pressure leading to increased venous capillary pressure. The decreased perfusion pressure leads to ischemia which causes further tissue damage creating a vicious cycle with positive feedback loop.

Ischemia leads to hypoxia and depletion of intracellular energy stores. Anaerobic metabolic pathways are activated to compensate leading to acidosis. Further reduction in the ATP production leads to shut down of sodium-potassium ATPase channels that maintain the cellular polarity and osmotic balance. Loss of cellular polarity leads to influx of chloride ions and cellular swelling. Increased cytosolic calcium accumulation causes lysosomal enzyme release and cell lysis.

Monitoring of ICP by slit catheter technique has a sensitivity of 94% and specificity of 98% when pressure gradient (∆P) of 30mm Hg is used for diagnosis.

Compartment Pressure Measuring Technique

Compartment pressure should be measured within 5 cm of the fracture and pressure within all 4 compartments of the leg should be measured.

Proper technique which includes proper positioning of the catheter within the compartment, proper setup of devices, proper zeroing is essential for correct measurement of intra-compartmental pressure. Otherwise catastrophic errors are likely.

The landmarks for insertion of needle for compartment pressure measurement are as follows.

Diagnosis is made if the difference between compartment pressure and diastolic pressure (∆P) is less than 30mm (McQueen 1996) or if the intra-compartmental pressure is above 30mm of Hg (Whitesides 1975).

Recently 35% false positive rate was reported when compartmental pulse pressure of <30mm Hg on single measurement was used in patients with acute fractures with no clinical evidence of compartment syndrome. (Whitney 2014)

Treatment

Timely diagnosis and dermatofasciotomy is essential to ensure optimum outcomes.

Initial treatment consists of removal of circumferential dressings and elevation of the limb to the level of heart.

The limb should not be elevated in impending compartment syndrome as it further reduces pressure gradient.

Techniques of fasciotomy

Dermatofasciotomy

Percutaneous fasciotomy

Percutaneous fasciotomy is contraindicated in trauma patients

Techniques of dermatofasciotomy

Mubarak’s 2-incision, 4-compartment fasciotomy

Matsen’s parafibular 4-compartment fasciotomy

Fibulectomy-fasciotomy

Fibulectomy-fasciotomy is contraindicated in trauma patients.

Mubarak’s 2-incision, 4-compartment fasciotomy of leg

Medial incision for release of deep and superficial posterior compartments made 2 cm posterior to the posteromedial border of tibia. Incise from proximal tibia to the musculotendinous junction of Achilles tendon. Protect saphenous nerve and vein. Incise fascia to release superficial posterior compartment. Elevate the soleus from the medial border of tibia to expose the deep posterior compartment and release the fascia.

Lateral incision for release of anterior and lateral compartments made 2 cm anterior to the fibular head. Incise from fibular head to the distal fibula Protect superficial peroneal nerve distally. Elevate the anterior flap. Incise fascia to release anterior compartment anterior to the anterior intermuscular septum. Elevate the posterior flap, incise the fascia along the posterior border of fibula to release the lateral compartment.

Matsen’s parafibular dermatofasciotomy.

After fasciotomy, the viability of the muscle should be ascertained by the 4 C’s: Color, Consistency, Contractility and Capacity to bleed.

The wound left open and spring sutures placed to progressively close the wound.

Patient returned to operation theatre at 48 hours to reassess the wound.

Fasciotomy increases the duration of hospital stay, escalates the costs, increases the chance of infection and interferes with fracture healing.

Recently the need for release of all four compartments in all patients have been questioned and an algorithmic approach consisting of selective release of compartments have been put forward. (Tornetta 2016)

Tornetta 2016 algorithm advises measurement of diastolic BP preoperatively, measurement of ICP, fasciotomy of anterior and lateral compartments, measurement of ICP of posterior compartments and medial incision if the pressure difference with diastolic BP (∆P) is less than 30mm Hg and to avoid release if ∆P is more than 30mm Hg. Close post-operative monitoring by clinical examination every 2 hours is necessary. They did not recommend this algorithm in centres with no facility to monitor the intracompartmental pressure in the post-operative period.

Complications

Delayed or missed diagnosis may lead to complications such as renal failure, ischemic contractures and limb loss.

Cause of delayed or missed diagnosis

Unconscious or inebriated patients

Regional or general anesthesia

Polytrauma

Soft tissue injuries

Inexperience

Over-reliance on clinical symptoms and signs

Complications of delayed or missed diagnosis

Muscle necrosis and contractures

Permanent neurological deficit

Infection

Chronic pain

Amputation

Death

The side effects or complications of fasciotomy are muscle weakness, chronic venous insufficiency, adherent scars, impaired sensation, ulceration, increases in duration of hospitalization and costs and the delay in definitive treatment.

Recent Advances

Newer diagnostic tools include the following.

Near-infrared spectroscopy (NIRS) uses differential light reflection and absorption characteristics to estimate the proportion of hemoglobin saturated with oxygen 2-3 cm below the skin. It is currently FDA approved for noninvasive continuous monitoring of pressure in the intracranial and somatic tissues. Skin pigmentation and thickness of subcutaneous fat may interfere with NIRS.

Radio-frequency identification implants are minimally invasive devices with sensors to measure pressure, oxygenation etc. that are microfabricated into silicon substrate. It uses RFID technology to transmit the data collected.

Newer methods to reduce pressure

Methods to decrease intramuscular pressure

Anti-inflammatory drugs like indomethacin

Ultrafiltration catheters as treatment- Tissue ultrafiltration by insertion of small diameter hollow fibers into the compartment, connected to suction to remove interstitial fluid to reduce compartment pressure.

Foot pumps

Mannitol

Diuretics

Decompression by dorsal skin fenestration or pie crusting in compartment syndrome of foot.